FR2660985A1 - METHOD FOR CAPTURING AND EVACUATING FERMENTATION GAS IN A DISCHARGE TANK, ESPECIALLY HOUSEHOLD GARBAGE, AND DEVICE FOR TRANSPORTING FLUID, IN PARTICULAR ALLOWING ITS IMPLEMENTATION. - Google Patents

Abstract

The device collects and evacuates fermentation gases emanating from waste, such as household refuse (1) dumped and stacked in successive layers in an open ditch (2) provided for this purpose. A well (6), placed in the middle of the pile of refuse, is used as a collecting system for the said fermentation gases and is connected by piping (17) (forming a drain) to a gas collector (4) situated on the edge of the ditch. The fermentation gases are evacuated to the gas collector by suction. The piping (17) can accommodate any variations in the position of the collection well (6) with respect to the level of the pile of refuse. The piping (17) is placed overhead at a sufficient height above the outside surface of the pile of refuse to allow working machines to pass over it.

Description

The present invention relates to a method for capturing and

  evacuation of fermentation gas in a discharge pit, in particular of household waste, and a device allowing in particular the implementation of this method. Household garbage, when not destroyed by incineration or recovered, is generally stored in discharge troughs These discharge troughs may be for example clay cells that are filled as and when, it is covered, cyclically, on the surface, by layers of earth (clay, topsoil or any other backfill), these layers of earth being most often compacted with the steamroller The environment becoming a subject more and more Sensitive to public opinion, we have been led to develop these landfills with devices for capturing the fermentation gases of household waste These fermentation gases are now burned, to avoid any nuisance in the vicinity of these landfills It is used to do this devices essentially comprising wells for capturing gaseous fumes from the refuse pile, these capture wells being connected by piping s suction to a biogas collector located on the clay earth bordering the discharge pit and from which the gas is transported to a burner or flare These suction pipes or connecting ducts called " drains "are

  generally pushed a few tens of centimeters

  below the surface of the garbage pile (buried drains) or

  placed on said surface (surface drains).

  In the case of buried drains, it was found that the pipes were mechanically highly stressed during the degradation of the garbage, since during the "active life" of the garbage pile, the level of the latter is in constant lowering, a phenomenon which is aggravated by the aforementioned deposition of layers of soil, as well as by the passages of the steamroller It is for this purpose that in most of these devices, flexible connections have been provided between the drain , on the one hand, and the well and

the collector, on the other hand.

  These displacements and stresses generate at the level of the drain cracks and fissures, which make completely inefficient all the installation of capture The fermentation gases are not any more sucked at the level of the well, the aspiration pump aspiring, meanwhile, essentially surface gas and air, through the plugs that constitute these cracks or breaks This is why current devices are very unreliable, so

  that they initially require a significant investment.

  Surface drains, they pose enormous problems of exploitation, since it is necessary to

  dismantle and reassemble them at each filling operation-

  in the ground, or whenever you want to

  vehicle, such as a steamroller, on the landfill.

  An object of the present invention is therefore to overcome these major drawbacks. It proposes, in particular, a method for capturing fermentation gases which is very reliable and which

  does not interfere in any way with the operation of the landfill.

  The invention essentially proposes for this purpose to achieve an air drain between the capture well and the collector Such an aerial connection ensures ground service by the gear, without risk to the drain.

  Moreover, this dug-up drain is no longer subject to any request.

  when the pit is backfilled with layers of soil.

  Finally, this air drain is, by nature, much more

  accessible as a buried drain, which allows monitoring

  launches constantly, in operation, and facilitates

possible repairs.

  More particularly, the Applicant proposes an air link device between a fixed point (the collector on the edge of the pit) and a point variable in level (the capture well, intended to collapse over time), this device has a beam supported by

  supports, said beam being intended to carry a pipe-

  with which it can possibly be confused on all or part, and admitting a certain angular displacement with respect to said supports, so that the level drop of one of the supports, related to the variable point is accompanied by a slope of the beam, without risk

  internal force for said beam.

  It should be noted that such an aerial device has a structure

  very simple, advantageously modular, and also has the advantage of being able to be recovered once the exploitation of the pit is completed, that is to say once the garbage discharge of which said pit has been filled

  has leveled off (about five years).

  link, if the pits are distributed on each side of the same dike, on which are located collectors, simply rotate the entire device around its fixed support on said dike and put it back into operation on the pit on the other side of the first pit compared to

the dam.

  The subject of the present invention is therefore a process for capturing and evacuating fermentation gases emanating from refuse, in particular housewives, discharged into a pit provided for this purpose, in which: the fermentation gases are sucked into said pile garbage; said sucked gases are evacuated to collect them, from the belly of the refuse pile to the edge of said pit; characterized in that the evacuation of said gases within the heap

  garbage is carried out using aerial drains.

  Another object of the invention is also a device

  tif of transporting a fluid, allowing in particular the implementation of this method and comprising a beam element carried by at least two supports distributed in its length and each secured to fastening means now at least partially said beam level relative to said supports, said beam carrying, over at least a portion of its length between said supports a fluid transport pipe, characterized in that the fastening means allow an angular displacement of said beam relative to said supports, as well as a axial sliding of said beam relative to at least one of said supports. Advantageously, the attachment means associated with a

  support comprise at least one tangential bearing pulley

  said beam The attachment means associated with a

  support comprise two pulleys of substantially parallel axes

  and between which is passed a beam, said beam being tangentially in contact with each of these pulleys. Preferably, the attachment means allow axial sliding of the beam relative to each of said supports. The device comprises retaining means intended to limit or prevent the axial sliding of the beam relative to the two supports under the effect of its own structure. weight and / or limit the deflection of the beam The retaining means comprise at least one cable, in tension between the two supports and at least one connecting member integral with the beam, the connecting member comprises a

  pulley pivotally mounted on a stirrup integral with the beam.

  The retaining means may in particular comprise several cables each associated with a connecting member, each cable being in tension between the two supports and the

link with which it is associated.

  Advantageously, the fastening means are adjustable in level relative to the support with which they are associated. The supports are, on at least one of their parts, posts associated with adjusting sleeves.

level of attachment means.

  Preferably, the pipe is associated at one of its ends with a fluid inlet tube and / or at its other end with a fluid outlet tube, a fluid inlet and / or outlet tube being a tube flexible flexible adapted to accompany its deformations the possible movement of the beam relative to its supports A flexible tube is at least partially wound on itself, possibly enclosed in a protective housing, according to a spiral whose height can be deformed in the where the pipework is associated with a fluid inlet tube, said inlet pipe is connected to a fluid capture member

  placed on or within an environment likely to affect

  At least one of the supports is carried by a soleplate disposed on or within the medium

subsidence.

  Preferentially, the beam is merged,

  over all or part of its length, with the piping.

  The piping is made of reinforced polyester, polyethylene

  high density or any material with the characteristics

  Mechanical and chemical problems in accordance with the fluid

  vehicle and the necessary ranges.

  Another object of the invention is a device

  Tif of the above type for the implementation of the method, comprising, in a pile of junk a well which serves as a capture member of the waste fermentation gas, said well being connected to a gas collector on the edge of the pit in which the said garbage has been discharged. Advantageously, the fermentation gases are discharged from the capture well to the pipe at least partially via a hollow tube integral in translation with one of the supports and able to slide in said well to accompany the possible movement of said support.

  Other features and advantages of the invention

  The following description will emerge from the following description and

  which is not limiting in nature This description

  should be read with reference to the accompanying drawings: In these drawings: FIG. 1 is a sectional view of a device according to the invention for capturing fermentation gases in a refuse collection pit, this device having been represented in two different positions; FIG. 2 is a top view of a set of refuse collection pits, these different pits being associated with the same collector of fermentation gas, each of these pits being associated with at least one device

as in Figure 1.

  Figure 3 is a view of a detail of the device of

Figure 1.

  Figure 4 is a sectional view along line IV-

IV of Figure 1.

  Figure 5 is a view similar to that of Figure 1 of a device for capturing fermentation gases

  according to a second embodiment of the invention.

  Figure 6, finally, is a plan view according to the

line IV-VI of Figure 5.

  Referring more particularly to Figures 1 and 2, it is seen that 1 has referenced piles of household waste discharged into pits 2 which are alveoli

  of clay delimited laterally by dikes 3.

  The gas collection device shown in said figures comprises along a dike 3, which borders a series of pits 2, a collector duct 4 This collector duct 4 is associated with a fan (not shown), which may also be a pump for sucking the fermentation gases into said collecting ducts 4,

  to the torch of a burner 5.

  Each of the dump pits 2 is, according to

  area, associated with one or more catchment wells 6.

  Each well 6 is a substantially cylindrical bed of pebbles

  that, which is buried deep within the heap

  of garbage 1, preferably to the central part of

  ci, and which is arranged so that its axis is substantially perpendicular to the bottom of the pit 2 with which it is associated Each well 6 is associated with a drain 7

  extending axially from the interior of said well 6, to

  beyond the surface of the corresponding pile 1 A drain 7 is a

  hollow tube with a diameter of approximately 20 cm and is

  8, which it crosses axially, said upright 8 having a parallelepipedal shape with a square base and extending at least partly in the garbage stack 1 Said amount 8 is based on a thickness of the pile 1 through a sole 9, which terminates at its end inside said pile 1 This sole 9 is a square section plate, centered on the axis of the drain 7 which passes through a bore 10 provided for this purpose, the edges of said soleplate 9 being parallel to the edges of the cross section of the upright 8 The upright 8 is also also held in place relative to the pile 1 by means of a surface plate 9a mounted on its middle part and

  substantially identical to the sole 9.

  The drain 7 extends beyond the upright 8 by a portion 11 forming a column of a height equal to about 9 m The drain 7 and said pole portion 11 are two parts of the same tube separated from each other by a device

  sealing 12 to prevent parasitic air intake.

  At its end opposite the sole 9, the upright 8 is extended by four radial stiffening ribs 13 regularly distributed around the drain 7, which extend parallel to the longitudinal faces of the upright 8 and in a triangular shape, from their base to the level from the end surface of the upright 8 to their top, which is

  on the drain 7 just before the sealing device 12.

  The drain 7 is also associated with a bypass tube 14, which extends from said drain 7, in a part thereof at the upright 8, through said upright 8, and then along it. bypass tube 14 extending beyond said upright 8, by a flexible tube 15a wound spirally around the pole portion 11 This flexible tube 15 opens at its end farthest from the branch tube 14, in a 16 cylindrical tubing

in reinforced polyester.

  This pipe 16 also plays the role of a hollow beam, referenced by 17 as a whole, and extending from (and beyond) said portion 11 forming a pole to a post 18 carried by the dike 3 The axes of the portion 11 and the post 18 are separated from each other by a distance of 15 m, the length of the beam 17 being approximately equal to 18 m The axis of the beam 17 is at a distance of about 3 m from the device The beam 17 is extended on each side of the pipe 16 by a carrier portion 19 separated from said pipe 16 by a sealing device 20, which is produced by means of a solid buffer disposed at the interior of said hollow beam 17 and held in place therein by means of a flange clamping said beam 17 on its outer surface The middle section of the beam 17 is also the middle section of the

piping 16.

  The pipe 16 is connected to its end closest to the pole 18, to the collector 4 by a tube

  flexible 15b wound spirally around the pole 18.

  The post 18 is a tube substantially identical to the tube of the drain 7 and the portion forming a post 11 It is carried by an amount 21 identical to the upright 8, said upright 21 extending partially into the dam 3, parallel to the upright 8, and being arranged next to the collector 4 This upright 21 is itself carried by a sole 22 taking

  support in the clay constituting the dike 3.

  As can be seen more particularly in FIG. 3, each of the posts 11 and 18 is associated with a sleeve 23 which is adjustable in level with respect to said posts and

  carrying two pulleys 24 or 25 whose axes are perpendicular

  relative to the axis of said sleeve 23 and are distributed in the length thereof. Between these two circular pulleys 24 and 25, pivotable on their axes, is passed the beam 17 whose surface is tangentially in contact with each of these two pulleys 24 and 25 These two pulleys 24 and have wide grooves of round section with a rounded shape,

  which allows a slight transverse movement of the pipe-

  16 and the beam 17, with respect to the posts II and 18.

  Towards the free end of the posts 11 and 18, extends from one ring 27 to another, a sling 28 in tension, connected to the beam 17 by means of a pulley 29 in which said sling 28 is past, said pulley 29 being mounted on a pivoting bracket 20 secured to the beam 17 to

  level of the middle part of it.

  In operation, the fan (not shown) sucks the fermentation gases collected in depth in each of the piles 1 via the capture wells 6, to the burner 5 burner, through the drain 7, the bypass tube 14, the flexible tile 15 a, the piping

  16, the flexible tube 15b and the main manifold 4.

  When the garbage pile 1 collapses during its "active life", the sole 9 and the upright 8 are brought down, the catching device passing, for example, if one refers to 1, from its position shown in solid lines at its position shown in phantom. The level change of the upright 8 causes the drain 7 to slide in the well 6, so that the portion 11 forming a post drops in level with respect to the The distance between the fastening means formed by the pulleys 24 and 25 associated with the post 18 and with the column portion 11 increases, the two end portions 19 of the beam 17 sliding axially with respect to said pulleys 24 and 25; that allows the angular displacement of said beam 17, in the pulleys 24 and 25, relative to the posts 11 and 18 The possible sliding of the beam 17, under the effect of its own weight, in the parts 24 and 25 is otherwise limited by the acti the sling 28 is retracted onto the pulley 29 and the stirrup 30, which also serves, of course, to prevent the beam 17 from catching an arrow on its middle part While the distance between the two ends of the flexible pipe 15 it has also increased, said spiral pipe 15 has unwound, the flexible hose 15b

  accompanying the movement of the beam 17.

  The aerial connection of piping thus carried out adapts itself to the eventual collapse of the refuse pile.

  1, without any risk of internal stress for the pipe-

  Such a device can in particular withstand 10 to 15% of slope, which makes it possible, in the context of garbage dumps, to wait for one or two years to replace said device or simply restore it to a state of service. for example by raising the sheath 23

  associated with the portion 11 forming a pole.

  FIGS. 5 and 6 show a device according to a variant of possible embodiment of the device previously described. For the elements of this second device which have been shown and which can be found on the device according to the first embodiment, has taken the same reference numerals increased by 100. This device comprises, in a pile of household waste 101, discharged into a pit 102, a capture well (not shown), inside which plunges a drain 107 connected by a bypass tube 114 and a flexible tube 115a to a pipe 116, which is the median part of a beam 117, this pipe 116 being connected, at its end opposite the flexible tube 115a, to a collector

  main 104, by a second flexible tube 115 b.

  Over the entire length of the beam 117 are regularly distributed trays 150 On each plate 150 is mounted a pulley 151 carried by a stirrup 155 and in which is passed a sling 152 stretched between the heads of the posts 111 and 118, on which it is mounted by means of a clip 154 on which is provided for each sling 152 a ring 153 Each of the pulleys 151 is offset relative to the others, so that the slings 152 extend from the post 111 to the post 118 without interference with one another Such a device allows, of course, to make beams 117 more

wide range.

  It is clear that the devices that have just been described in the particular context of the capture of fermentation gases from garbage dumps, can be used in a much more general way, in particular for the transport of fluid with the aid of aerial piping between two supports, at least one of which must be able to adapt in level It is of course quite conceivable that each of the two supports of such devices is variable level In particular, for the devices for capturing and evacuating fermentation gas in a discharge pit, that of the two supports which is on the clay edge delimiting said pit may be subject to changes in level, especially due to the collapse of the clay.

Claims (13)

  1 Process for the capture and evacuation of fermentation gases emanating in particular from domestic refuse (1, 101) discharged into a pit (2, 102) provided for this purpose in which: the fermentation gases are sucked into said pile garbage (1, 101); said sucked gases are evacuated for collection from the bunch of garbage (1, 101) to the edge (3, 103) of said pit (2, 102); characterized in that the evacuation of said gases (1, 101) is carried out using aerial grains (15a, 16, 15b, 115a, 116, b). 2 Device for transporting a fluid for carrying out the method according to claim 1, comprising a beam element (17, 117) carried by at least two supports (11, 18; 111, 118) distributed in its length and secured each fastening means (23, 24, 25; 1124, 125) now at least partially holding said beam (17, 117) level with respect to said supports (11, 18; 111, 118), said beam (17, 117); ) carrying, over at least a part of its length between said supports (11, 18; 111, 118) a pipe (16, 116) for conveying fluid, characterized in that the attachment means (23, 24, 25) 123, 124, 125) allow angular displacement of said beam (17, 117) relative to said supports (11, 18, 111, 118), as well as axial sliding of said beam (17, 117) with respect to at least one   said supports (11, 18; 111, 118).   3 Device according to claim 2, characterized in that the fastening means (23,24, 25; 123, 124, 125) associated with a support 11, 18, 111, 118) comprises at least one pulley (24, 124 tangentially bearing said beam (17, 117). 4 Device according to claim 3, characterized in that the attachment means (23, 24, 25; 123, 124, 125) associated with a support (11, 18; 111, 118) comprise two pulleys (24, 25; 124, 125) of substantially parallel axes and between which is passed a beam (17, 117), said beam (17, 117) being tangentially in contact with   each of these pulleys (24, 25; 124, 125).   Device according to one of Claims 2 to 4,   characterized in that the attachment means (23, 24, 25; 123, 124, 125) permit axial sliding of the beam (17, 117) relative to each of said supports (11, 18; 111, 118). 6 Device according to claim 5, characterized in that it comprises retaining means (28, 29; 151, 152) for limiting or preventing the axial sliding of the beam (17, 117) relative to the two supports (11). , 18; 111, 118) under the effect of its own weight and / or to limit the boom deflection (17, 117).   Device according to claim 6, characterized   in that the retaining means (28, 29; 151, 152) comprise   a cable (28, 152), in tension between the two supports (11, 18; 111, 118) and at least one connecting member (29,   ; 150, 151) integral with the beam (17, 117).   8 Device according to claim 7, characterized in that the connecting member comprises a pulley (29, 151) pivotally mounted on a stirrup (30, 155) integral with the beam (17, 117).   9 Device according to one of claims 7 or 8,   characterized in that the retaining means comprise several cables (152) each associated with a connecting member (150, 151), each cable (152) being in tension between the two supports (111, 118) and the connecting member (150, 151) with which he is associated.   Device according to one of Claims 2 to 9,   characterized in that the fastening means (23, 24, 25; 123, 124, 125) are adjustable in level relative to the support   (11, 18, 111, 118) with which they are associated.   11 Device according to claim 10, characterized   in that the supports are, on at least one of their parts (11, 18; 111, 118), posts associated with sleeves (23, 123) for adjusting the level of the attachment means (23, 24, 25, 123, 124, 125).   12 Device according to one of claims 2 to   11, characterized in that the pipe (16, 116) is associated at one of its ends with a fluid inlet tube (15 a, 115 a) and / or at its other end with a tube (15 b, 115). b) fluid outlet, an inlet tube (15a, 115a) and / or fluid outlet (15b, 115b) being a flexible tube adapted to accompany by its deformations the possible movement of the beam ( 17, 117) relative to its supports (11, 18; 111, 118).   13 Apparatus according to claim 12, characterized   in that a flexible tube (15a, 15b; 115a, 115b) is at least partially wound on itself in a spiral   whose height can be distorted.   Device according to one of claims 12 or   13, in the case where the piping (16, 116) is associated with a fluid inlet tube (15 a, 115 a), characterized in that said inlet tube (15 a, 115 a) is connected to a member (6) for capturing a fluid disposed on or within a medium susceptible to subsidence.   Device according to claim 14, characterized   in that at least one (11, 111) of the supports is carried by a sole (9) disposed on or within the medium   (1, 101) susceptible to collapse.   Device according to one of claims 2 to   16, characterized in that the beam (17, 117) is merged over all or part of its length, with a pipe (16, 116).   17 Device according to one of claims 2 to   16, characterized in that the pipe (16, 116) is in   reinforced polyester or high density polyethylene.   18 Device according to one of claims 2 to   17, for the implementation of the method according to claim 1, comprising, in a pile of garbage (1, 101) a well (6) which serves as a collection member of the fermentation gases of household waste, said well (6) being connected to a gas manifold (4, 104) on the edge of the pit (2, 102)   wherein said household waste has been discharged.   19 Apparatus according to claim 17, characterized   in that the fermentation gases are discharged from the collection well (6) to the pipework (16, 116) at least partially via a hollow tube (7, 107) integral in translation with a (11, 111) supports and fit   sliding in said well (6) to accompany the movement   possible medium of said support (11, 111).